Ok here's the official version of how "Dumont " got it's name.
Dumont Sand Dunes: Relief Feature, 30 Miles NNW of Baker, CA.
The feature is West of the site of Dumont, named on the Silurian Hills (1956) 15’ Quadrangle
The United States Board on Geographic Names (1984,PP4) approved the Name “Dumont Dunes” for the feature.
DUMONT: Site of Dumont; locality 30 Miles N of Baker, CA. (Lat; 35*41’ 35” N, 116*10’ 30”W near the West line of Sec 31, T19N-R8E.
The site is named on the Silurian Hills (1956) 15’ Quadrangle. The place was along the Tonapah and Tidewater Railroad and was named for Harry Dumont, an official of the “Pacific Coast Borax Company.
Source: Durham’s Place Names of California Desert Counties- Page 55